of berlin-grttnewald



Oct. 1, 1929. M s m- ET Re. 17448 TELEPHONE Original Filed Inch 26 1925 3 1 Oct. 1, 1929. MASSOLLE Re. 17,448

TELEPHDNE Original Filod'larch 26, 19:25 sheets-sheet 5 JOSEPH MASSQLLE, OF

' plurality of frequencies so that Reissued Oct. 1

UNITED STATES PATENT mcr.

AND JOSE]? ENG-L,

IBERLIN-GfiUNEWALD, HANS VOGr'l, OF BERLIfi-WILMEBSDORF, OF BERLIN-GBUNEWALD, GERMANY,

AssmNonafBY mnsun ASSIGNMENTS. TO FOX, 0]? WO ODSIBUBGH, NEW YORK 'rnnnrnonn filed July 20, 1929,

The invention relates to improvements in telephones and particularly to loud speaking or other receiving telephones which are adapted to reproduce sound, such as speech and music, with great faithfulness and absence of distortion.

In its preferred form the iIIVGDtlOI1' comprises an electrostatic telephone, the invention, however, not being limited to this form.

In our Patent No. 1,550,381, Aug. 18, 1925, electrostatic telephone, granted Aug. 18, 1925, we have disclosed a telephone, thediaphragm of which is subdivided by annular clamping rings into a plurality of ring shapedportions which are adapted to vibrate independently of each other, these diaphragm portions each having a natural rate of vibration corresponding. to some frequency within the acoustic range.

By the provision of a suificient numberof diaphragm annuli' each having a different natural rate of vibration, the diaphragm will have resonance peaks corresponding to various fundamental tones and their overtones, and by the provision of a suitable dampin factor, the resonance peaks thus formeil will be flattened, so that the vibration of the diaphragm will correspond quite closely with the various frequencies which are to be reproduced throughout, the acoustic range.

The present invention is in some aspects thereof an improvement upon that disclosed in our said co-pending application. In ac? cordance with the present invention a plural ity of diaphragm portions are provided, each of which possesses no decided natural rate of vibration as a whole. Each of these dia phragm portions or members resonates to a one of these diaphragm members or portions may re-C spond to various frequencies within one range While another diaphragm member or portion responds to various frequencies extending through a different range. Thisis accomplished by the provision of diaphragm members or portions of irregular shapes; and in the preferred form of the invention this is accomplished by subdividing the diaphragm into a plurality of annular portions each of which is of a varying width. .Thus the diatrically arranged clamping cent diaphragm portion,

distortion and preferably by m. 18,620, filed mm. 26, 1925. Application for reissue Serial no. 379,863..

position by eccenrings so mounted phragm may be clamped in as to provide a plurality phragm portions each in width progressively through say 180,or generally speaking throughout the arc of some radialangle of the annulus, the diahragm annulus decreasing progressively in width throughout the remainder of its angular extent. With such an arrangement the of which may increase to resonate to throughout an extended range. In the preferred arrangement, the highest individual natural rate of vibration of one diaphragm annulus or portion will be rather close to the lowest natural rate of vibration of an adjable to produce a device in which there is a fairly uniformvariation of thenatural rates of vibration of. the diaphragm from a very low level toa high range.

An object of the invention is the provision of improved devices of the character referred to above.

Other objects the provision of improved devices whereby sound may be reproduced with a of a. diaphragm, the total area of whichis suflicientto render the use of an amplifying horn unnecessary, when the device is used as a loud speaker for reproducing the sound in an auditorium or the like.

The invention accordingly consists in the improved arrangements and combinations of parts and features of construction all as will be more fully described in the following specification, and as will be particularly pointed out in the appended claims;

In order that the invention may be more thoroughly drawn .to the accompanying drawings forming part of the invention and illustrating by Way of. example certain preferred embodiments of the invention.

Referring to the drawings. Fig. 1 repre sents a face view of oneform of telephone,

it being thus poss1-- understood attention is herebv.

of annular diavarious diaphragm portions may be caused substantially all frequencies level within the acoustic of the invention comprise V telephone, certain parts Fig. 3, taken on an enlarged scale;

"and

Fig. 5 is a partial front elevation of a modified form of electrostatic telephone, Fig. 6' is a'section taken online of Fig. 5. 1

Referring to the drawings, the construction shown inFigs. 1 and 2 is illustrated as applied to. an electro-m agnetic; telephone,

but it should be understood that this is merely by way of. example. The diaphragmj 1 is supported about its periphery-and also at a point ,eccentric with respect to the diaphragm. A supporting plate 2 is illustrated ri h of the member 7. and v at its outer the'innerleflgta of the clamping ring 4.

- The avlng a peripheral forwardly extending flange, against which the edge portion of the diaphragm seats and to which it is secured, as

for example, by means of the clamping r ng 4 between which and the surface of seating flange 3 the edge portion of the d1aphragm is clamped by suitable means such as screws 5. The plate 2 is also'provided with a forwardly extending boss 6, :against which the diaphragm is clamped by suitable means'such as a circular plate 7, a screw 8 being illus- I vtrated as extending through member 7 and '35 the dia hragm' and into the boss 6..

It be noted that the center line C of member 7 and-'bossfi is aced somewhat away from the center C o the d a' rtion of the diaphragm whic 1s V to vi rate is according width, bounded at its inner .edge by the In the form ofeonstruction shown in the I drawing, electro magnets 9-9 are indicated,

d1 tic-11y, as being suppprted by plate 2, in position to. actuate the iaphragm m use to vary g currents thro theielectro-magnet circmt. y desired number-pf these electro-magnets may beuaed, the same preferably bemg spacedat points intermediate the clamping member 7 and'the outer clampi ring It'should be understood that,-i'f t e invention em electro-statie telephone Instead of an electromagnetic telephone, capacity surfaces take the place of the electrofollowing figures of the drawing.-

construct-ions being des reinlfter in connection with the In the construction illustrated 1 and 2 the width of the vibratory an electro-static ly an annulus of 'varydia hragm' annulus'causesthe same to have, fl rent natural rates of vibration which vary in accordance with the varying widths of the diaphragm as explained. The diaphragm will accordingly resonate to a plurality of different frequencies throughouta more or less extended range.

Referring next to the form of construction shown in Figs. 3 and 4 of the drawings, a construction is shown in which the diaphragm is subdivided into. a plurality of annular portions,'each of varying width, and each having a range comprising a plurality of natural rates of vibration. This construction is shown as applied to an electrostatic or con denser type of telephone, which constitutes the preferred form of construction.

In the construction illustrated, a fixed condenser plate 10 is shown with which cooperates movable diaphragm 11. This diap ragm constitutes the movable element of the electro-static telephone and in the ,pre-

ferred form of construction the diaphragm is formed .ofinsulating material carrying a coating 12 of electrically conducting ma-f terial. Preferably the diaphragm is formed 1 ofan exceedingly thin disc of mica, which is preferably coated with a suitable conducting metal. The conductive coating may, forexample, be a thin silver coat deposited on the diaphragm from a solution compris- 'ing silver nitrate and other substances, the invention, however, not'being limited in this respect. The sheet of mica used in the dia-'- phragm is preferably of a thickness of only about 3/100 of a millimeter, while the diameter of the diaphragm is preferably quite large, as for example about meter, the

invention not, however, being limitedto such dimensions. It is noted,'-however,. that mica is particularly well adapted for use in our preferred construction, since a uniform sheet of mica may be obtained, by a splitting process so that it is possible to ob-' tain a sheet ofa thickness as slight as 1/ 100 of a millimeter, and of a diameter, for example,- meter. Such extreme thinness and large diameter are-possible because of the high tensile strength of the mica. The advantages- 1 of mica for the desired purpose are ex- 7 filained in our co-pending application, Serial 0. 518,425, referred to. In'our preferred construction the diaphragm is placed under I a .considerable tension, which may be nearly as great' as the elastic limit of the mica, it

being noted that the elastic limit of mica is exceedingly high in relation to its tensile strength The mica stands such high tension exceedingly well in practice. It should be noted-that the exceeding thinness of themica diaphragm makes for lightness and; absence of inertia, and it also should be noted that the' hard smooth surface of the mica better-fits the same for the propagationtof sound waves than would a porous or non-uniform surface" The diaphragm is clamped against suitintegral with the fixed plate preferably are 10. In the construction illustrated, plate is provided with an annular outer rim portion 13, which is concentric with able seating surfaces, which may be seated. In the construction shown the plate 10 is also provided with a boss 14 against which the diaphragm is clamped,

noted that, in

is clamped against this seating portion situated with respect with respect to the V, 17, an annular vibrating portion will thus be provided'between seating portions 14 and ,17, which will be of a widthwhich varies continuously, first increasing uniformly throughout a portion of it s circumference and then uniformly decreasing in width throughout the remainder of its circumference. v

Another annular vibrating diaphragm portion is formed between the eccentric ring 17 and an outer seating ring, which, in the present construction, takes the form of a ring 19, which may be concentric with the plate 10 itself. Thisoutcr diaphragm portion, bounded by the eccentric ring at its outer edge, will, therefore,

inner edge and the concentric ring at. its be a diaphragm portion of ring shape, generally speaking, but of a varying width. The space between ring 19 and the outer edge of the plate 10,

sired, as an provided align with the eccentric boss 14 on plate in the construction illustrated, is utilized for tensioning and clamping the diaphragm. Phe diaphragm is clamped in position by means of a construction 'which comprises pressure rings or the equivalent, this preferably taking the form of a spider having 'an outer.annular rim 20 and radiating spokes or arms 21. This spider construction is with a boss 22 which is adapted to 10'when the rim 20 of thespider is aligned with the outer edge of plate 10. The spider is also provided'with an eccentric ring 23, which is adapted to align with the eccentric ring 17 on plate 10. ,All of the parts described of the spider may be formed, if deintegral metal construction, which may, for example,

cast. v

In assembling the plate, clamping member therefor, is positioned against the plate 10 with conductive coating 12 on the side of the dia phragm away from the plate. The spider diaphragm and I the plate and against. which the edge portion of the diaphragm which is somewhat the corresponding the greatest width and vice versa.

'very readily be the diaphragm. while the ring may then be secured to the plate by means i of screws 24 or other suitable securing devices passing through the rim portion 20 of the s ider and through the edge portion of the diaphragm and into the rim portion of plate 10. Preferably insulating material 25 is provided about each of the screws 24 to prevent the formation of any creeping paths for electrical currents along the screws from the spider to the fixed plate. The conductive coating 12on the diaphragm may exteiid radially only so far, if desired, as the'inner edge 26 of the faced clamping portion 20' of the rim of the spider member, or if desired the conductive coating may be continued to the outer periphery of the diaphragm, which may be at it being noted that the mica body or base of the diaphragm serves as an insulation beteen the parts. Y

The diaphragm may be tensioned by suitable devices such, for example, as peripherally arranged members 27, which may be carried or engaged by screws 28 threaded through suitable openings in rim 20-of the spider member. These pressure devices 27 may be of wedge shape or other suitable shape, and are caused to press against the diaphragm to tension the latter as" desired. Plate 10 may be provided with recessed portions 29 in alignment with the pressure devices 27 the diaphragm being pressed into theserecesses by members 27 as the tensioning proceeds. Preferably the diaphragm is tensioned up to a elastic limit of the mica, as stated above.

' The fixed plate 10 is provided with capacity surfaces intermediate the clamping or seating portions of the plate, which capacity surfaces are to serve as the fixed plate member of the device with which the adjacent portions of the conductive coating carried by the diaphragm will co-act. As shown, these fixed capacity surfaces may take the form of ring shaped members integral with the body of plate 10. These capacity sur faces are preferably positioned intermediate the clamping or seating portions of the plate, the fixed capacity rings being widest at points at which In the construction shown, one fixed capacity annulus 30 1s intermediate the boss -14 and the seating ring 17, and an outer capacity, annulus 31. is positioned intermediate rings 17 and 19. As stated, these capacity surfaces are preferably formed of varying widths. Thus the annular surface- 30 may be bounded on the inside by 'a circle 32, the center of whioh'is at a polnt 32', 30 is bounded on the outer side by a circle 33, the center of which is at a'dilferent. point such, for example, as point 33'. Similarly the outer capacity annulus the outer edge of the plate,

point quite close to the rings of varying widths,

diaphragm annulus has- 31 is of varying width having its inner and outer ed es bounded by circles which vare formed a out difler'ent points as centers. Itwill be noted that the construction described gives the capacity surface in each instance a varying width, which may be widest at. a point at which the corresponding "diaphragm' portion is the'widest. I y

The seatin rings or portions 14, 17 and 19 and the ed capacity 's'urface rings and 31 are provided with .very accurately phragm.

faced upper surfaces so that the diaphragm when at rest will be separated from the fixed capacity surfaces by a very small gap,

being set back from This gap, for example, may be a matter of a ve few one hundredths of a millimeter. he accurate establishment of this distance, in the construction illustrated; is provided by the accuracy with which the seating surfaces and fixed capacity.surfaces of plate 10 are finished,

and variation in the 'widthof the gap between the diaphragm and the fixed capacity surfaces is prevented by the fact that the parts which establish the gap are all formed .of metal, .havingthe me 'co-efiicient of expansion throu hou't.

The close-a just the fixed capacitysurfaces causes a damping of the vibrations of the diaphragm, which damping-is desired, but not to as great an extent as would be provided by the con-' struction described. Accordingly, the dampmg efi'ect may besomewhat reduced by the provision of suitable openings throughg the' 'condenser plate 10 through which'the air in the gap between the diaphragm'and the fixed capacity surfaces may escape to greater or less extent during thevibration of .the dia- In the construction shown the openings for the escapeof the-airpreferably take the form of concentric circular channels extending entirely through the fixedcapacity ringgportio'ns 30 and 31 ofthe plate 10. These circular grooves 34, in the caseof' the inner condenser ring 30, may, for exam ple, be formed about the'fpoint 32 as a center. Some of these circular channels will extend entirely through 3609, entirely around the fixed capacity portion 30 of the plate,

' while some of these circular channels 34 will extend through less than 3609 of length since the .'W'lll run out through-the outer periphera surface of ring 3Q,-w'i-thf 'hich they are eccentric. The circular channels 34',.form'ed through the outer capacity-ring 31, are simi- .lar. The rings of. metal'intermediate the circular channels 34 and 34' are, of course, held together by suitable connecting por tions of the metal which maysbridge across the various circular channels atpoints which may, for example, be out of alignment with each otherr r Imthe construction described, the vibratethe least width of of the diaphragm to ing diaphragm portion intermediate the seat ing portions, 17 and 18 of the plate will have 'yarious individual rates of vibration extendmg through one range of acoustic frequencies, while the outer diaphragm annulus be tween seating rings 17 and 19 will have various other natural individual frequencies extending through ajdifierent range of. the acoustic frequencies. The outer-d aphragm annulus as arranged will have ahigher range of frequencies than the inn'er diaphragm annulus and the arrangement referably is such that the lowest natural equency of the outer annulus is nearly the same as the high- "iest natural rate of the inner annulus. This equalit of the lowest natural rate of the outer-diaphra m portion with the highest natural rate 0 the next adjacent inner dia' phragm. portion may be arranged by making the inner diaphragm annulus substantially equal to the greatest width of the outer diaphragm annulus.

With such an arrangemept as many eccentric diaphragm rings may be arrangedone with another as is required, so that the range of natural vibration of the diaphragm may extend substantially from the lowest up to the highest acoustic frequencies which will have to be reproduced. In case such an arrangement requires a telephone having too great a total diameter; a plurality of such telephones may be used, and this is in fact the preferred arrangement.

In the construction as illustrated, the highest frequency of one diaphragm portion may, as stated, besubstantially equalto the lowest natural frequency of the adjacent diaphragm annulus. This is evidenced by substantial equality of the smallest width of the inner diaphragm annulus, indicated at 1105 d", with the greatest width of the outer diaphragm annulus, indicated at d, the reference characters d, d, d and (1 being used to indicate the respective widths of the diaof the diaphragm along the central vertical -axis, referring to Fig. 3. With this a!- rangement, however, anabsolutely uniform variation of 'the 'natural'rates of vibration vofthe entire diaphragm is not produced; 1 15 Uniform. variation throughout the entire diaphragm is possible when the widths of 'one diap'hragm*portion overlap the widths of the adja'cent portion to the extent of 90 of angular displacement, and such an air-. 'rangement may readily be "accomplished within the resent invention. This arrangement may he used when two or moretelephones'are used in place of a single one because of the fact that one telephone would I be too -la rge,jas stated above. In this case the several telephones may have theirqvidths of vibratory diaphragm portions displaced to the extent of 90", with reference to one another.

'To make the above matter of overlapping widths somewhat clearer, it should be noted that each diaphragm annulus increases pro gressively in width from its greatest width,-

as at (1 to its least width, at d, where d and d are illustrated as being onxthe vertiapproximately equal, not the greatest width,

d, of the outer annulus, but the Width of the outer annulus at a point intermediate d and (.l", in which case width d would of course be less, than width (.1 of the outer annulus aligned therewith, and greater than width (1.

The diaphragm rings may and preferably 4 are so calculated that approximately equally riplieral flange of rim large surfaces are operative at all frequencies whereby all frequencies are reproduced in proper proportion one to another.

A modified form of construction is'shown in Figs. 5 and 6. In this case the diaphragm 11, having a conductive coating 12, is secured in position between the fixed condenser plate-10' and a spider member. The diaphragm is shown as clamped about its outer periphery,-by devices which are concentric with the diaphragm itself, and about one inner circle which is eccentric with the diaphragm so as to produce a single vibratory diaphgram annulus of varying width.

In the construction illustrated, the plate 10 has a ring portion 35 which is secured to an outer flanged ring 36 by means, for example,,of screws 37 extending through a pe- V 35 and into ring 36, insulating material 38 referably bein used about screws 37 and etween the a acent faces of rim 35 and ring-'36. The clamping or pressure applying member comprises an outer concentric rim portion 39, together with radial arms 40. An eccentric ring 41 "spider member by ",screws 44 which extend peripherally around is carried by the arms 40. 1 Clamping and pressure applying members. 42 extend through this ring and are adapted to press the adjacent portion of the diaphragm against correspondingly positioned seats 43,

formed in the fixed condenser member 10. The ring 36 to which the fixed plate 10" is secured isfastened to the rim 39 of the means, for example, of

the device. The diaphragm is secured under tension at its outer edge by means of clamping and tensioning devices 45, 45'

which extend through the rim 39 of the spider member in two concentric rows one within the other. a

These clampmg mem ers m y c mprlse away from either the d aphragm and may be forced more or less tightly against'the diaphragm by the small screws 45, 45. Suitable recesses 47, 47 are provided in the face of ring '36 and rim 35 of the fixedplate construction respectively in which the adjacent portions of the diaphragm will be pressed when the clamping members are tightened. Screws 42, extending through the eccentric ring 41, are similarly caused to operate pressure applyingmembers .48, which are similar to members ,46 and 46'.

The plate 10' is provided with a fixed ca pacity surface 49 which extends in the form of a ring of varying width around the device intermediate the circles along which the diaphragm is clamped'at48 and 46. This annular capacity surface is only illustrated in part, since it will be understood that its width may vary connection with Fig. 3'.

diaphragm may be relieved by the provision of channels 50 which may beformed in a similar manner to the in connection with Figs. 3 and 4.

from the seating surfaces on 1 (iiaphragm will be clamped, adjacent the recesses 43 and 47 so as to establish a slight gap between the fixed capacity surface and the diaphragm as was throughout its angular ex-; tent in the same manner as was explained in Air in the gap between the fixed capacity surface and the channels 34, described The capacity surface 49 is set back slightexplained in connec tion. with the construction shown. in Figs;

3 and 4. The construction may be completed by a cover plate 51 which 1105 maybe secured' to the rim flange 36 of the plate construction by means of over the plate construction together with the screws 37 and 44. p

In the construction described, the diaphragm is both clamped'and placed under I the desired tension by suitable adjustment of the pressure devices 48, 46 screws or other devices passing through the diaphragm itself. It will, of course, be understood thatsimilar clamping and tensionin Figs. 3

form of a spiderinstead of in the form of asolid plate, in which case the member 10 will comprise the fixed capacity surface rings 49.

It will be understood that electrical connections are tobe suitably made to the fixed and movable members of the condenser teleph ne Thus it the term shown n Fig ing means may be used, if desired, in con-- nection with the form of construction shown and 4. The fixed plate member 10' may, if desired, be constructed in the screws 52 so as to cover and 46, no

the rim 35 connectedto the hub 53 by means of radial arms which carry scribed.

device may be suitably amplified as b 3 and 4 oneconnection is, of course, made to the plate 10 and the other connection to a suitable point such as the rim 20 of the spider, which, of course, is in contact with the conductive coating 12 of the diaphra In the form shown in Figsf5 and 6 suita le connection may bemade with the plate member-10' and with the rim' 39 of the spider construction, p

The device, as described, in its various forms, particularly in the forms illustrating the same, as an electrostatic telephone, is particularly well adapted for use as a loud speaker or sound reproducer, which may be employed, for example, to reproduce sound in theaters or concert balls, or the like. When so used, sufliciently loud reproduction may be given without theuseof any ampli-' fying horns or the like, whereby the errors of reproduction due to such devices are ob- 'viated, and this obviously true because of the considerable size of the diaphragm which is preferably employed and by the employment of two or more similar devices if necessary, asadescribed above. In this connection it will, of course, be understood that the electrical currents operating the means of the usual vacuum tube ampli rs, so that the diaphragm portions may be givena suflicient amplitude of vibration in case loud reproduction is desired. It will also be notedthat the device, because of its large number of natural rates of vibration, pro

vides for vibration of the diaphragm in resonance with a considerable number oi of a considerable breadth is indicated by the scope of the appended claims. i

What we claim is: i

1. In a telephone, the combination of a diaphraifi, a plate, and means for clamping the dia agm to theplate, in spaced relation thereto; comprising rings eccentric to the diaphragm to provide vibratory diaphragm portions having different natural rates of vibration.-

2. In a telephone, the combination of a diaphragm, a plate, and means for clamping the diaphragm immovably to the plate, aboutthe periphery of the diaphragm and at a point eccentric with respect to the diaphr so as to provide a complete annular 'aiplgragm portion of varying width In said plate and surrounding said point. i

3. In a-teleplione, the combination of a diaplate, and means-for clamping P 5 1 the d ap gmtothe plate, about the periphery of t e diaphragmnnd about a circle eccentric with thereof,'soas'to phragm portion around said circle.

provide a. vibratory diaezrtending completely 4. In a telephone, the combination of a I diaphragm, a plate and means for so clamping the diaphragm to the plate as to prov de aplurality of complete ring shaped diaphragm portions, eccentric to the diaphragm, of varylng' widths and having dif' ferent natural rates of vibration.

5. In a'telephone, the combination of a respect to the diaphragm and-intermediate the center and periphery acoustic frequencies which, are to be" rediaphragm,,a member to which the same is produced whereby resonance peaks are secured, and means for so clamping the diaformed throughout theentire range of frephragm immovably to said member as to quencies which are to be reproduced. Di'sprovide a vibratory diaphragm portion in tortion in reproduction is, however, prethe shape of a complete annulus of a width vented by the damping efiect provided, so [uniformly increasing throughout a portion that the resonance Accordingly, in a graph or characteristic uniformlyd curve portra the operation of the dimaindel'. of the aphragm at all uencies reproduced,the' nulus. tops oflthe resonance peaks will be con- 6. In. a telephone, the combination of a nected together by a smooth curve which is diaphragm, a member to which the saine'is substantiallythesame as that which would secured, and means for so clamping the dia representthe correct vibration of the dip immovably to said -member as to aphragm for'the-various v diaphragm had no natural rates of vibra the shape of a complete annulus of varying tion at'all. That is to say, we consider it width, whereby the diaphragm will have a throughout the reangular extent of the animpractical-to so arrange such a large di-' pluralityof difierent natural of vibraaphragm as weprefer to-use, that-the nat tion throughout its area. 7

ural to of vibration of the same will be. 7. Ina telephone, the combination .of a

outside the acoustic range; and, accordingly, diaphragm, a member to which the same is we provide for as large a number of natural secured, and means for so clamping the diarates of vibration within the acoustic V phragm to said member as to provide a pair btain the efiects deas is posible and Y each in the shape of an annulus of varying -It should be understood that the invention width, one surrounding the other, each anis not limited to the exact details of the connulus having a plurality of differentnatural struction which have been particularl derates of'vibration, the rates of vibration to scribed, but that the same is considered which one annulus responds lying within of separately-vibratory diaphragm portions, 7

peaks will be flattened. of' the angular extent of the annulus, and

11 frequenci if the provide a vibratory diaphragm portion in one range, and the rates of vibration to wh1ch the second annulus responds lylng within a different range.

I 8. In 'a telephone, the combination of a diaphragm, a member to which the same is secured, and means. for so clamping the diaphragm to said member as to provide a plurality of separately-vibratory diaphragm portions, each in the shape of an annulus of varying width, said annuli being radially one Within the other, each annulus having 7 a range of frequencies to which it resonates,

diaphragm,

- from said ,means forsecuring said parts in. POSHDIOII,"

means for clamping openings the lowest natural frequency of one annulus being close to the highestvnatural frequency of the adjacent annulus on one side thereof.

9. In a telephone, the comb-ination of 'a a fixed condenser plate having responding to a aseating surface and a capacity surface, and

said diaphragm" against said seating surface so as to provide a vibratory annular width separated from said capacity surface by a slight gap.

10. In a telephone, the combination of a diaphragm having an efiective vibratory portion of annular shape with varying Width, an annular capacitysurface separated diaphragm by a slight gap, and

with said diaphragm under tension.

11. In a telephone, the-combination of a diaphragm'of irregular shape, calculated to resonate locally to various frequencies, a

diaphragm portion of-varying:

.jsulatlng material coatlng thereon, a

spaced a slight distance to which the second annulus responds lying within a different range, the outer annulus higher range of frequencies than the inner.

1,5..In a telephone, .thediaphragm means, annuli of varying width, one radially within the other. supporting means, and means for securing said annuli thereto about their peripheries, each annulus having a plurality combination of of different natural rates of vibration, the range of frequencies of one annulus being.

different from the range of another.

16. In a telephone, the combination of diaphragm means, comprising a, plurality of portions of irregular shape, supporting means, and means for securing said portions thereto about all their. edges,

comprising a plurality of 17. In a telephone," the combination of diaphragm means, comprising a pluralityof portions of irregular shape, formed of inand means for securlng' saidportions in position from said plate,

with the conductive coatings on the opposite side from said plate, said coating being connected together electrically.

plate closely adjacent t-o'said diaphragm to produce a damping effect, said plate having therethrough to somewhat relieve the damping effect, and means forsecuring said partsin position with said diaphragm under tension. N

12. In a telephone, the combination of a diaphragm of irregular shape, resonate locallytovarious frequencies, said diaphra m being of insulating material with a conductive coating, a condenser plate'closely adjacent tot-he insulated side of said diaphragm, and iheans for securing said parts in position;

13. In a telephone, the combination of a diaphragm having a plurality of separated parts each having a plurality of different natural rates of vibration, supporting means, and means for securing said diaphragm thereto under tension, and for separating secured, I and means the parts of said diaphragm.

14. In a telephone, the co ination of a diaphragm, a member to which the same; is for so clamping the diaphragm to said member as to provide a pair of separately-vibratory diaphragm portions, each in the shape of an annulus of varying Width, one surroundingthe other, each annulus having a plurality of different natural rates of vibration, the rates of vibration to which one annulus responds lying within one range, and the rates of vibration calculated to j 18. In a telephone, the combination of diaphragm means, comprising a plurality of portions of irregular shape, formed of insulating material I coating thereon, each portion being adapted having a conducting fixed condenser plate, and-1 and having a conducting,

to resonate to a difierent range of fre-.

quencies, capacity surfacesspaced slight dis tances from the insulated sides of said portions, and means for securing said parts in position and for electrically connecting together said capacity surfaces, and said diaphragm means port1ons. V

19. In an electrostatic telephone, the combination of movable plate means, comprising a plurality of irregularly shaped diaphragm portions, each portion being adapted to resonate to a different range of fre 'quencies, capacity surfaces spaced slight dis tances therefrom, and means for securing ing capacity surfaces,

said parts connecting together said capacity surfaces,

and the portions of said movable late" means;

20. In an electrostatic telephone, the combination of diaphragm means, comprising a plurality of annuli of varying Width, one surrounding the. other, fixed means provideachcomprising an annulus of varying width, spaced slight distances from said diaphragm annuli, andmeans for securing sald means in position.

21. In an electrostatic telephone, the com-,

bination of diaphragm-means, comprising a plurality of annuli of varying width, one surrounding the other, fixed means providing capacity surfaces, each comprising an annulus of varying Width, spaced slight disin position and for electrically tances from said diaphragm annuli, and

extending therethrough from said capacity surfaces.

22. In an electrostatic telephone, the combination of a fixed condenser plate having .an annular capacity surface and. annular seating surfaces at the outer and inner sides of said capacity surface, a diaphragm comprising a movable condenser element, and diaphragm-securing means comprising a spider construction having a rim portion adapted to be secured to said fixed plate, and means carried by said spider construction for clamping said diaphragm against said seating surfaces with the diaphragm spaced slightly from said capacity surface.

23. An electrostatic telephone with struc ture according to claim 13 and in which the diaphragm comprises conductive means forming a condenser plate cooperating'with other condenser plate means secured in respect to the supporting means.

24;. An electrostatic telephone with structure according to claim 13 and in which the diaphragm comprises forming a condenser plate cooperating, with other condenser plate means secured in respect to the supporting means, said last named plate means being relatively rigid and having perforated portions cooperating with the diaphragm portions respectively and arranged in such proximitytq the diaphragm as to have a limited damping efl'ect thereon.

25. An electrostatic telephone with structure according to claim 13 and in which the diaphragm comprises forming a condenser plate;

26. In a telephone, the combination of a diaphragm having a-plurality of separated parts each havin a plurality of different nat 'ural rates of vi ration, supporting means,

and means for securing said diaphragm thereto under tension and for separating the parts of said diaphragm, each of said diaphragm 'parts being responsive to various frequencies and having no. decided natural rate of vibration asa whole. 7

27. In an electrostatic telephone, the com,- bination ofa diaphragm comprising conductive means and having a plurality of separated parts, each .of said diaphragm parts .having a plurality df diflerent natural rates of vibration and said parts being-responsive to various frequencies but having no decided natural rate of vibration as a whole, supporting means, means for securing said diaphragm' thereto under tension, andmeans for separating the parts of said diaphragm, comprising relatively rigid condenser. plate means.

28. In an electrostatic telephone, the comconductive 'meanslast named plate conductive means hination. of a diaphragm comprising conductive means and having a plurality of separated parts, each of said diaphragm parts having a'plurality of different natural rates phragm along the dividing lines of the dia- 'phragm portions.

29. An electrostatic telephone with, structure according to claim 13 and in which the diaphragm comprises conductive means forming a condenser plate cooperating with other condenser plate means secured in res ect to the supporting means, the diap ragn being calculated to resonate-locally to various frequencies'and under the control of a limited damping effect provided by said means.

30. electrostatic telephone with structure according to claim 2, the diaphragm and plate comprising. opposed capacity areas.

31. An electrostatic telephone with structure according to claim 11, the diaphragm and plate comprising opposed capacity areas. 7

32. An electrostatic telephone with structure according to claim 12 and in which the vibratory areas of the diaphragm are provided with a conductive coating, the edges of the diaphragm at the securing means being free of such coating.

' 33. An electrostatic telephone with structure according to claim 13 and in which the diaphragm cooperates with relatively fixed capacity areas, the vibratory areas of the diaphragm being provided with a conductivecoating, the edges of the diaphragm at the securing means being free of such coating.

34. An electrostatic telephone withstructure according to claim 13 and in which the diaphragm cooperates with a relatively fixed capacity member, portionsof said fixed member engaging the diaphragm to divide the diaphragm into a plurality of strips comprising the separated diaphragm parts.

35. An electrostatic telephone with structure according toclaim 13 and in which'the diaphragm cooperates with a relatively fixed capacity member, portions'of said fixed member engaging the diaphragm along extended predetermined lines to divide the diaphragm into a plurality of strips comprising the sep-- arated diaphragm parts.

3 36. An'electrostatic telephone with-struct'ure according to claim and in which portions on said plate the diaphragm to tions on said plate engage into a plurality of divide the diaphragm strips eachpossessing no decided natural rate I telephone with structo claim 11 and in which por- In testimony whereof, we have signed our names to this petition and sfiackification.

' JOSEPH SSOLLE. HANS VOGT. J ()SEF ,ENGL.

tions on said plate engage the diaphragm to a divide the diaphragm into a plurality of strips each possessing no decided natural rate of vibration.

40. An electrostatic ture according tocalim 11 and in which portions on said plate engage the diaphragm to divide the diaphragm into a plurality of separately vibratory portions each possessing no decided natural rate of vibration.

41. An electrostatic telephone with structure according to claim lland in which por-- engage the diaphragm along extended predetermined lines to 'divide the diaphragm into a plurality of strips each possessiing no decided natural rate of vibration. j

42. In an electrostatic telephone, the combination of a diaphragm comprising conductive means and having a plurality telephone with strucof separated parts, comprising separately vibratory strips, each of said diaphragm rates of vibration and said parts being responsive to various frequencies but having no natural rate of vibration as a whole, su porting means, means for securing sai di phragm thereto under tension, and means for prising relatively rigid condenser means.

43. In an electrostatic telephone, the combination of ,a diaphragm comprising conductive means and having a plurality of separated parts, comprising extended relatively narrow areas, each of said diaphragm having a plurality of difierent natural rates of vibration and said parts being responsive to various frequencies but having no decided natural rate ofvibration as a whole, supporting means, diaphragm thereto under tension, and means for separating the parts of said diaphragm, comprising relatively rigid condenser plate means. 3

parts having a plurality of different natural decided separating the parts of saiddiaphragm, complate means for securing said 7 

